Merge pull request #2 from Luzenna/master

Merge gui stuff, ass
Fixed bugs in pawn movements....
Issue #10: Alternate black and White player

IsWhiteToMove is not'ed after a move is done.
Issue #11: Add pawn promotion

Always promotes to Queen in GUI.  Needs some GUI stuff to make it work
correctly.
Issue #6: Moves for Bishop

Added the possibility to move the bishop around the chess board.
Issue #7: Moves for Rook

Added the possibility to move the rook.
Also moved part of the logic to find correct moves for pieces that moves
over several squares in multiple directions into an abstract class that
inherits from piece.
Issue #5: Moves for Queen

added the possibility to move the queen.
Issue #8: Moves for king

Moves for king is implemented.
Issue #4: Moves for knight
Create README.md
Merge pull request #3 from vegah/master

GIMME ALL YOUR GOODIES